Street sweeper pick-up broom and elevator suspension



Jan 16 1968 OSTAMNY 4- STREET SWEEPER PICK-UP BROOM AND ELEVATORSUSPENSION Filed May 16, 1966 3 Sheets-Sheet 1 INVENTOR. Smou EMA/Y s.TAMNY 3 363 274 Jan. 16, 1968 STREET SWEEPER PICK-UP BROOM AND ELEVATORSUSPENSION Filed May 16, 1966 s Sheets-Sheet 2 INVENTOR. Z6 -$/Mo/vEMA/y Jan. 16, 1968 s. TAMNY 3,363,274

STREET SWEEPER PICK-UP BROOM AND ELEVATOR SUSPENSION Filed May 16, 1966v 3 Sheets-Sheet 5 LQGUZ I NVEN TOR. Suva/v IZMNY United States Patenttion of California Filed May 16, 1966, Ser. No. 550,404 12 Claims. (CI.1584) This invention relates generally to street sweepers, and morespecifically concerns improvements in suspension systems for trashdisplacing apparatus such as street sweeper brooms and trash elevators.

It is a major object of the present invention to provide an improvedsystem for lifting a street sweeper broom, and also a trash elevator,and for flexibly supporting the broom in sweeping position. Basically, asingle mechanism is provided to combine the functions of lifting thebroom and elevator for travel and of adjustably resiliently supportingthe broom in sweeping position with low spring rate. Past suspensiondevices have not, to my knowledge, incorporated these functions in asingle mechanism, and as a result have lacked the unusually advantageousfeatures of construction and function as well as the improved resultsafforded by the present invention.

Basically, the invention contemplates the combination with a streetsweeper vehicle of trash displacing apparatus such as a broom or trashelevator, together with means to support and move the apparatus betweenraised position for travel and lowered position in which the apparatusis operable to displace trash, such means including a torsion bar fortransmitting loading imposed by the apparatus accompanied by torsionaldeflection of the bar providing resilient support for the apparatus inlowered position. Typically, a flexible line such as a chain transmitsimposed loading to suspend the apparatus during movement between raisedand lowered position, and rotatable tubular structure is provided towind and unwind that line for raising and lowering the apparatus, thetorsion bar being connected to resist rotation of the structure actingto unwind the line. As will be seen, the torsion bar typically has dualor parallel segments enclosed within the tubular structure, to provide alow rate spring suspension for a broom, the latter being raised andlowered by axially spaced portions of the line wound on rotary sheaves,the broom having such support in down position independently of trashelevator apparatus that is subject to raising to travel position withthe broom. The low rate spring afforded by accommodation of the torsionbar in the combination has the advantage that the broom is much morefree to deflect in response to variations in the contour of the sweptsurface.

Other features and objects of the invention include the provision of anadjustable device operable to control load resisting torsionaldeflection of the torsion bar, thereby to control the degree of let downof the rotary broom against a street surface; and the provision of anadjustable device operable through one of the suspension line portionsto dilferentially control tilting of the broom axis relative tohorizontal.

These and other objects and advantages of the invention, as well as thedetails of an illustrative embodiment, will be more fully understoodfrom the following detailed description of the drawings, in which:

FIG. 1 is a side elevation showing incorporation of the invention on astreet sweeper vehicle;

FIG. 2 is an enlarged side elevation partly broken away to show detailsof the invention, the broom and trash elevator apparatus being inlowered position;

FIG. 3 is a fragmentary side elevation showing trash discharge into avehicle transported dirt box;

FIG. 4 is a vertical section taken on line 44 of FIG. 2;

FIG. 5 is a view like FIG. 2, but with the broom and elevator apparatusin raised or traveling position;

FiG. 6 is a fragmentary side elevation illustrating sweeping of trashinto the conveyor or elevator;

FIG. 7 is a perspective showing of the broom and elevator suspensionmechanism together with the actuator therefor;

FIG. 8 is a section taken on line 8+8 of FIG. 7;

FIG. 9 is a section taken on line 9-9 of FIG. 7; and

FIG. 10 is a section taken on line 1010 of FIG. 9.

Referring first to FIGS. 1 and 2, the street sweeper vehicle 19 is shownto include a front cab 11 and a rear frame 12, the latter carrying adirt box or debris chamber 13. The latter dumps through a bottom reducedoutlet indicated at 14, and normally closed by agate not shown. A gutterbroom 15 is shown as suspended beneath the vehicle cab 11 and suitablydriven in rotation at 16.

Trash displacing apparatus to be lifted and lowered in accordance withthe invention typically includes a rotary broom 17 having a generallyhorizontal axis 18. Means to support the broom is shown to include arms19 pivotally connected at 20 to vehicle structure 21. The arms typicallyinclude housings containing a drive chain for transmitting drive torotate the broom in the direction as indicated by the arrow 22 in FIG.6, the broom being supported at its axially opposite ends by the arms19. FIGS. 2 and 5 respectively show the lowered and raised positions ofthe broom.

Trash displacing apparatus also typically includes a trash conveyormechanism generally indicated at 23. That .echanism includes an endlessconveyor 24 such as a belt extending about drums 25, one of which may besuitably driven as by a hydraulic motor in order to transport theconveyor 24 in the loop pattern illustrated, so that the conveyorflights 26 will lift trash and dirt in the direction of the arrow 27, asseen in FIG. 6. In this regard, the conveyor mechanism includes acarriage 28 having an inclined panel 29 adjacent which the conveyorflights 26 move upwardly to lift trash for discharge into the dirt boxas indicated by the arr-ow 30 in FIG. 3. The carriage 28 has suitableside and cover panels 31 and 32 to enclose the movable conveyormechanism. The cover panel is interrupted to define an opening 33 at thelevel of the broom 17 so that the broom may extend in said opening andbetween the side panels 31, as, for example, is seen in FIGS. 4 and 6.Finally, the conveyor carriage has forwardly elongated narrow skids 35connected therewith at the lowermost portion thereof for engagement withthe street surface 36. Tongue and groove connections at 37 between theskids and the side panels 31 of the carriage 23 facilitate heightadjustment of the skids relative to the carriage and also relative tothe broom. The carriage 28 has pivot connection at 38 with panelstructure 39 on the vehicle 10 to allow pivoting of the carriage 28between the positions seen in FIGS. 2 and 5. As is clear from FIG. 3,panel 39 may define a wall of the dirt box 13.

The invention contemplates the provision of means to support and movetrash displacing apparatus between raised position for travel andlowered position in which the apparatus is operable to displace trash,such means including a torsion bar for transmitting loading imposed bythe trash displacing apparatus accompanied by torsional deflection ofthe bar providing resilient support for the apparatus in loweredposition. As regards the trash displacing broom 17, such ,means includesa flexible line typically having axially spaced chain portions 40connected at 41 to the arms 19, as seen in FIGS. 2, 4 and 5. The supportmeans also typically includes structure such as axially spaced sheaves42 which are rotatable to wind and unwind the chain portions 40respectively to raise and lower the broom v17 suspended by the cableportions.

The sheaves 42 are typically integral with a horizontally andtransversely elongated tubular member 43 so as to. rotate therewith,that member receiving a torsion bar connected to resist rotation of thesheaves and tubular member acting to unwind the chain portions 40. As isclear from FIGS. 2 and 7, the cable portions 40 are taut when the broom17 is in lowered position, so as to suspend at least some of the Weightof the broom while allowing the latter to deflect downwardly andupwardly in conformance with torsional constraint imposed by the torsionbar. As seen in FIGS. 8 and 9, the torsion bar has dual segments 44 and45 enclosed by the tubular member 43 and arranged to provide anextremely low rate spring for the pick-up broom in sweeping position.Torque is transmitted from the member 43 to the bar segment 45 at theattachment location 46, such torque being transmitted along the lengthof the segment 45 and then transferr'ed at block 47 to the torsion barsegment 44. Block 47 is rigidly attached to the'end portions 45a and 44aof the torsion bar segments, and is free to rotate within the tubularmember 43. Such transferred torque is then transmitted the length ofsegment 44 to a torque take-out element in the form of a crank 48rigidly attached to the end portion 44b of the segment 44. The crank iscarried by a bearing 49 journaled within the bore 50 of a bearing sleeve51 carried by the tubular member 43. The crank 48 has a shoulder 52engageable with adjustable stop 53 to limit rotation of the torsion bar,the vehicle frame 12 supporting the stop 53.

The invention contemplates the provision of an adjustable deviceoperable to control load resisting torsional deflection of the torsionbar, thereby to control the degree of letdown of the broom against astreet surface. That device typically includes a holder part such as thecrank 48 integrally rotatable with a section of the torsion bar, as forexample end portion 44b thereof, together with a stop part such as stop53 to limit rotation of the holder part, one of such parts beingadjustably shiftable relative to the other. In the example shown in FIG.7, the stop part is shiftable in the directions indicated by the arrow54, such shifting being accommodated by the jackscrew 55 pivotallysupported against axial motion at 56 to a plate 57 carried by the frame12. When the jackscrew head 58 is turned, the screw 55 is rotated toshift the stop 53 for suitable adjustment to control the degree of broomletdown.

The invention also contemplates the provision of an adjustable deviceoperable through one of the line portions 40 to diiferentially controltilting of the broom axis with respect to horizontal. This adjustment isotherwise referred to as a so-called cone adjustment, whereas thepreviously referred to broomletdown control is known as strikeadjustment. The cone adjustment device comprises a take-up carried todiflerentially wind a line portion 40 atone of the sheaves 42. Forexample, the left line portion 40 in FIG. 7 has its end connected to athreaded part 59 of the device 60 advanced and retracted by a nut 61 ofthat device. The nut bears against a stop 62 carried by the left sheave42. Accordingly, the left line portion 40 is adjustably taken up or letdown to difierentially control tilting of the broom axis with respect tohorizontal.

Winding of the line portions 40 on the sheaves 42 is effected inresponse to operation of an actuator controlling rotation of the tubularmember 43 and the sheaves 42, these defining rotary structure. Theactuator typically includes another sheave 42a connected to rotate withthe tubular member 43, a drive 63 movable between advanced and retractedpositions, and a flexible line 64 to transmit force between the actuatorand the sheave 42a upon which the line 64 is wound. The drive 63 isshown to include a crank 65 pivoted at 66 to the frame 12, to-

. '4 f gether with a plunger rod 63 to the crank. The plunger 67 has apiston connected therewith within a fluid pressure cylinder 69 pivotedto the frame at 70. Referring to'FIGS. 2 and 5, pressure transmitted at71 to the cylinder 69 advances the plunger 67 to carry the pivot 72over-center with respect'to the pivot 66. Pivot 72 connects the line 64with the crank 65, whereby the trash displacing apparatus including thebroom and conveyor structure is positively held in raised position fortraveling. When fluid pressure is admitted to the cylinder 69 at 73, theplunger 67 retracts as seen in FIG. 2 for lowering the trash displacingapparatus.

In accordance with a further aspect of the invention, 7

the trash conveyor apparatus 23 is also raised and lowered in responseto rotation ofthe tubular member 43115 controlled by the actuator. Forthis purpose, left and right sheaves 75, as seen in FIG. 7, have lineportions 76 in the form of chains wound thereon, the lower ends of thechains connected at 77 to the trash elevator apparatus. The sheaves 75are integral with the tubular member 43 to rotate therewith. In loweredpositionof the apparatus 23, the line portions 76 are slack as seen inFIG. 2,.

whereby the elevator is supported against further downward motion bystop pads 78 carried by the vehicle frame. The broom 17 then floatsvertically with respect to the elevator mechanism, as accommodated bythe torsion bar.

Supports for the tubular member 43 include bearings and uprights 86.Vehicle side panels are indicated at 87.

I claim: j 1. In combination with a street sweeper vehicle, trashdisplacing apparatus, and a single means to support and move saidapparatus between raised'position for travel and lowered position inwhich said apparatus is operable to displace trash, said means includinga torsion bar for transmitting loading imposed by saidapparatus'accompanied by torsional deflection of said bar providingresilient support for the apparatus in lowered position only.

2. The combination of claim 1 in which said means includes a flexibleline to transmit said imposed loading so as to suspend the apparatusduring movement between said raised and lowered positions, and structurerotatable to wind and unwind the line respectively to raise and lowersaid apparatus, the torsion bar being connected to resist rotation ofsaid structure acting to unwind the line in lowered position only.

3. The combination of claim 2 in which said structure includes anaxially generally horizontally elongated member receiving said torsionbar, the line including axially spaced portions, said structureincluding axially spaced sheaves connected to said member for commonrotation another line portion operable to suspend the conveyor beingslack in conveyor lowered positions 6. The combination of claim 4,including an adjustable device operable to control loadresistingtorsional deflection of the torsion bar, thereby to control thedegree of letdown of the broom against a' street surface.

7. The combination of claim 6 in which said device includes a holderpart integrally rotatable with a section of the torsion bar, and a stoppart to limit rotation of the holder part, one of said parts beingadjustably shiftable relative to the other.

8. The combination of claim 2 in which said structure includes generallyaxially spaced sheaves rotatable together to wind and unwind said lineportions, said apparatus comprising a rotary street sweeping broomhaving a generally horizontal axis, said means including pivoted 67having pivoted connection at a arms supporting the broom at axiallyopposite ends thereof, said line portions supporting said arms.

9. The combination of claim 8 including an adjustable device operablethrough one of said line portions to differentially control tilting ofthe broom axis with respect to horizontal.

10. The combination of claim 9 in which said device comprises a take-upcarried to difierentially Wind said line portion at a sheave.

11. The combination of claim 3 in which said actuator includes anothersheave connected to rotate with said structure, a drive movable betweenadvanced and retracted positions, and a flexible line to transmit forcebetween the actuator and said other sheave and wound by said othersheave.

12. The combination of claim 1 in which the torsion bar has dualsegments, and including an enclosure for the torsion bar, a flexibleline to transmit said imposed loading so as to suspend the apparatusduring movement between raised and lowered positions, the line being subject to winding and unwinding in response to rotation of said enclosure,the bar connected to resist unwinding of the line.

References Cited UNITED STATES PATENTS 2,199,703 5/1940 Hough 15482,286,245 6/1942 Wilson et a1. 15-83 2,327,879 8/1943 Farrar 1584 XCHARLES A. WILLMUTH, Primary Examiner. E. L. ROBERTS, AssistantExaminer.

1. IN COMBINATION WITH A STREET SWEEPER VEHICLE, TRASH DISPLACINGAPPARATUS, AND A SINGLE MEANS TO SUPPORT AND MOVE SAID APPARATUS BETWEENRAISED POSITION FOR TRAVEL AND LOWERED POSITION IN WHICH SAID APPARATUSIS OPERABLE TO DISPLACE TRASH, SAID MEANS INLCUDING A TORSION BAR FORTRANSMITTING LOADING IMPOSED BY SAID APPARATUS ACCOMPANIED BY TORSIONALDEFLECTION OF SAID BAR PROVIDING RESILIENT SUPPORT FOR THE APPARATUS INLOWERED POSITION ONLY.